G1 Gray

Dura-Bar G1 contains flake graphite in a matrix that is pearlitic with small amounts of ferrite. This is the softest grade of the Dura-Bar gray irons and is normally selected when excellent machinability is desired and the application requires moderate strength, hardness and resistance to wear. Excellent surface finishes can be achieved, which are especially significant where lapping is involved.

CENTER AREA 100x, etched in 5% Nitol EDGE AREA 100x, etched in 5% Nitol

The microstructure will contain Type VII, A, size 4-6 graphite as defined in ASTM A247. The matrix is pearlite with 5-20% ferrite. The rim will consist of Type D, size 6-8, graphite in a ferrite matrix with small amounts of pearlite. Chill carbides are less than 5% in any field at 100x and will be well dispersed.

Dura-Bar G1 can be oil quench hardened from 1575° F (885° C) to a minimum hardness of Rockwell C 40 on the outside of the bar. The inside diameter hardness will be less than Rockwell C 40. If quench hardness is critical to the application, Dura-Bar G2 is recommended. Dura-Bar G1 may be ferritize annealed to soften the material to approximately 130 BHN.